回答: 通过美军原始资料看长津湖美军陆战一师的伤亡 由 东方不亮 于 2019-07-08 9:12

首先我同意陆战一师确实受到重创，这个可以从你提供的资料和其它相关资料看出。 不过我不同意你说说的
怎么证明打残了？就是1950年12月31日的第三次战役，志愿军攻占了汉城，一度攻击至36线，陆战一师还趴在釜山休整呢。到1951年2月11日第四次中，陆战一师又在大邱当战略预备队，离前线足足180公里，当原州方向“联合国军”防线出现崩溃迹象时，李奇微急调美二师填补战役级缺口，陆战一师却纹丝不动，有这么“预备”的吗？直到1951年5月16日陆战一师才在第五次战役中登场，等于足足休整了小半年。 6park.com
原因是这两个资料
https://web.archive.org/web/20070716132000/http://korea50.army.mil/history/factsheets/marine.shtml
During the first three months of 1951, the 1st Marine Division participated in several U.N. offensive operations, first against North Korean guerrillas and later participating in an advance through the mountains of east-central Korea. From late April to early July, the division took part in the U.N. defense against a Chinese communist spring offensive, in which U.N. forces faced nearly 500,000 enemy soldiers. The Chinese offensive ended in mid-May with heavy enemy losses. 
51年的头三个月，陆战1师没有不干事，纹丝不动。 干了剿匪的工作，然后重新部署到前线。 6park.com
第二个资料
https://en.wikipedia.org/wiki/Operation_Killer  6park.com
During the week past, as PVA forces broke up X Corps’ Roundup advance and threatened to strike deep through the Han River valley, Ridgway had ordered the US 1st Marine Division up from Pohang, where it had been conducting anti-guerilla operations, to Chungju arriving on 18 February. Ridgway attached the division to IX Corps. The Marines were to relieve the US 2nd Infantry Division and 187th Airborne Regimental Combat Team (187th RCT) in the Wonju area, which on the 21st would fall within the zone of IX Corps. The 2nd Division and the 187th RCT then were to shift east and rejoin X Corps.[3]:306
这里明确的说明陆战1师在51年2月18号抵达前线接替陆军第二师。  6park.com
根据以上两个资料，你说的在第四次战役“陆战一师却纹丝不动” 是不对的。